tbuckley/cabot-search huggingface dataset:
Abstract P2008.1: Association Of Myocardial Stiffening With Impaired Relaxation In A Diabetic Murine Model Of Left Ventricular Diastolic Dysfunction
Authors: Tanmay Mukherjee, Sunder Neelakantan, Elizabeth Fugate, Emilio Mendiola, Aaron Burton, Diana Lindquist, Sakthivel Sadayappan, Reza Avazmohammadi
Journal: Circulation Research (2023)

Introduction: Left ventricular diastolic dysfunction (LVDD) is often manifested by impaired relaxation and myocardial stiffening in the left ventricle (LV). While impairments in the function of myofilament regulatory proteins are known to deteriorate LV relaxation, the effects of passive myocardial stiffening on the relaxation of active forces remain unknown. Methods: A diabetic murine model of LVDD (db/db, n=5) and wild-type mice (WT, n=5) were used to study the association between tissue-level passive stiffness and organ-level relaxation. Early transmitral flow velocity to mitral annular tissue velocity ratio (E/e’), measured by Doppler imaging, was used to assess LV relaxation. Cardiac magnetic resonance imaging was performed using a 7T Bruker scanner to estimate diastolic strains via image registration. Mechanical testing was performed on harvested LV free wall (LVFW) specimens to measure passive stiffness. Results: LVDD was confirmed by a high septal E/e’ ratio (Fig. 1A). The db/db mice presented an increase in passive LVFW stiffness measured as the tangent to the circumferential stress-strain curve at 30% strain (Fig. 1B). A positive correlation was observed between passive stiffness and E/e’ (Fig. 1C). End-diastolic strain calculations (Fig. 1D) corroborated LV filling impairment indicating significant reductions in circumferential LV strains (Fig. 1E). Conclusion: Passive stiffening may impair LV filling by not only restraining the passive stretch of the myocardium at diastole but also by decelerating the active relaxation. Further integrated in-vivo and ex-vivo studies of LVDD can deconvolute the “active” and “passive” causes of impaired relaxation.
Abstract P2192: Growth Hormone-releasing Hormone Receptor Antagonist Attenuates Cardiopulmonary Injury Induced By A Bsl2 Rvsv-sars-cov-2-s Virus Mimic Of Sars-cov-2 Infectivity
Authors: Jose Manuel Condor Capcha, Ali Kamiar, Emely Robleto, Tengjiao Cui, Ali Saad, Amanda Wong, Jason Villano, Andrew Pekosz, Mark J Ranek, Keith A Webster, Andrew Schally, Robert M Jackson, Lina A Shehadeh
Journal: Circulation Research (2023)

Background: COVID-19 causes severe pulmonary injury that can lead to acute respiratory distress syndrome. Growth hormone-releasing hormone receptor (GHRH-R) and its splice variant are expressed in murine and human lung and heart. GHRH-R antagonist, MIA-602, has been shown to modulate cellular immune responses to bleomycin lung injury and decrease inflammation in models of sarcoid granuloma. Using the BSL2-friendly rVSV-SARS-CoV-2-S of K18 hACE2tg mice to mimic native SARS-CoV-2 infection, we tested our hypothesis that MIA-602 attenuates cardiopulmonary injury in this COVID-19 model. Methods: Male and female K18 hACE2tg mice were inoculated with SARS-CoV-2 Washington (WA-1) native strain, recombinant VSV-SARS-CoV-2-Spike virus (rVSV-SARS-CoV-2-S), or PBS and lung viral load, weight loss and histopathology compared between groups (N=5-8). K18 h ACE2 tg mice infected with rVSV-SARS-CoV-2-S were subject to daily subcutaneous injections of 10 μg MIA-602 or vehicle starting at 24h post-infection. Pulmonary function was measured via whole-body plethysmography on day 0, day 3, and day 5 (n=7). Five days after viral infection mice were sacrificed; and blood and tissues collected for histopathological analyses, H&amp;E staining and ICAM-1 immunohistochemistry. T-test or One-way ANOVA-test was used for statistical analysis. Results: Native SARS-CoV-2 and rVSV-SARS-CoV-2-S presented with similar patterns of weight loss, infectivity (~60%) and histopathologic changes. Daily treatment with MIA-602 ameliorated weight loss, reduced lung perivascular inflammation and pneumonia, and decreased lung/heart ICAM-1 expression compared to vehicle. MIA-602 rescued respiratory rate, increased expiratory parameters (Te, PEF, EEP) and mitigated dysregulated measures of airway obstruction (Penh and Rpef) compared to vehicle. Conclusions: rVSV-SARS-CoV-2-S is an accurate and safe alternative to native SARS-CoV-2 for preclinical studies. Daily treatment with the synthetic peptide GHRH-R antagonist MIA-602 attenuates pulmonary dysfunction and heart inflammation in this new preclinical mouse model of COVID-19 pneumonia. We hypothesize that the molecular mechanism involves anti-inflammatory actions of MIA-602.
Abstract P3197: Sarm1 Deficiency Protects Mice Against Diabetic Cardiomyopathy: Potential Mechanisms Via Ameliorating Lipotoxicity
Authors: Keaton Minor
Journal: Circulation Research (2023)

Heart failure occurs at nearly twice the rate in diabetic patients as compared to normal patients. NAD levels are decreased in human and murine heart disease models including diabetic hearts. Strategies to raise NAD in these models have primarily focused on increasing NAD synthesis. Alternatively, inhibiting NAD consumption provides another viable path to increasing NAD levels in diabetic hearts. Sterile Alpha and Tir Motif Containing 1 (SARM1) is an NAD hydrolase that mediates axonal degeneration through NAD degradation and promotion of mitochondrial dysfunction. However, the role SARM1 plays in heart disease has not been investigated. We subjected male wild type (WT) and global SARM1 knockout mice (KO) to chronic diabetic stress induced by streptozotocin injections. We showed that 16-week diabetic stress promoted progressive decline in systolic and diastolic function as measured by longitudinal echocardiography. SARM1 deletion (diabetic KO) improved systolic and diastolic function of diabetic mice, despite similar glucose, and plasma aqueous and lipid metabolite levels as the diabetic wild-type mice. Diabetic KO hearts showed increased NAD levels, suggesting that SARM1 may be activated to promote NAD decline in diabetic hearts. Transcriptomic analysis identified 1948 differentially expressed genes in diabetic WT hearts, compared to non-diabetic WT hearts. Gene Module Network Analysis identified upregulation of fatty acid metabolic processes and suppression of genes involved in mitochondrial processes in diabetic hearts. We measured mitochondrial oxygen consumption rate and found suppressed mitochondrial respiration in diabetic WT hearts. SARM1 deficiency reversed the upregulated fatty acid metabolic genes, improved mitochondrial respiration, and elevated NAD levels in diabetic hearts. Genes such as CD36, HADHA, Acot2, and malonyl-CoA are all downregulated by SARM1 deficiency, indicating that SARM1 deficiency may relieve lipotoxicity by improving mitochondrial function and modifying metabolic transcriptional networks in diabetic hearts. Future analysis will shed light on how SARM1 contributes to lipotoxicity as a new pathogenic mechanism of diabetic cardiomyopathy.
Abstract P3055: Identification Of Cell-intrinsic Effects Of Clonal Hematopoiesis In Heart Failure
Authors: Wesley T Abplanalp, Bianca Schuhmacher, Sebastian Cremer, Maximilian Merten, Igor Macinkovic, Szumlakiwska Mariana, Andreas M Zeiher, David John, Stefanie Dimmeler
Journal: Circulation Research (2023)

Background: Clonal hematopoiesis of indeterminate potential (CHIP) is caused by somatic mutations in hematopoietic stem cells and associates with worse prognosis in patients with heart failure (HF). While, circulating immune cells derived from patients with HF harboring CHIP mutations show heightened proinflammatory signatures, it is unclear whether these signatures are derived from the relatively low number of cells harboring CHIP-driver mutations, or are indicators of a systemic pro-inflammatory activation associated with CHIP. Methods and Results: We assessed the cell-intrinsic effects of the most prevalent CHIP-driver gene (DNMT3A) mutant-carrying circulating immune cells in a total of 5 HF patients. Using a novel protocol to detect DNMT3A mutant cells on a single cell level (MutDetect-Seq), we show that CHIP mutations can be detected in all major immune cell types (e.g. T cells, monocytes, B cells, NK cells), with detected mutation similar to that predicted by traditional targeted DNA sequencing. DNMT3A mutant monocytes demonstrated the highest number of significantly upregulated genes relative to other cell types. DNMT3A mutant monocytes exhibit altered gene expression signatures associated with inflammation and phagolysosome function. Additionally, DNMT3A mutant carrying CD4+, but not CD8+ T cells, showed significant changes in gene expression patterns towards an activated and cytotoxic profile, which was validated in vitro. Finally, increased paracrine signaling pathways involved in amplifying inflammatory circuits are predicted between mutated and non-mutated monocytes, this was validated in vitro with further implications for cardiac fibroblast activation via aSMA and COL1A1 expression. Conclusion: This is the first study to decipher the genetic signature of DNMT3A-CHIP-driver mutation carrying circulating immune cells, thereby providing first evidence for the cell intrinsic effects of DNMT3A mutations on peripheral blood cell subsets in patients with HF. The altered gene expression profiles associated with inflammation and phagolysosome function of mutant monocyte, as well as skewing of mutated T cells towards effector cells provide novel insights into how CHIP may promote worse prognosis in heart failure patients.
Abstract EC.09: Single Nuclei RNA Sequencing Analysis Of <i>Mybpc-3-</i> Associated HCM To Identify Common Pathological Mechanisms In Human, Feline, And Murine Hearts
Authors: Samia Ali, Gayani Perera, Jason Laird, Rebecca Batorsky, Joshua A Stern, Samantha Harris, Michael T Chin
Journal: Circulation Research (2023)

Hypertrophic cardiomyopathy (HCM) is a common inherited cardiovascular disease characterized by unexplained hypertrophy, often associated with left ventricular outflow tract (LVOT) obstruction, ventricular tachyarrhythmias, diastolic heart failure, and sudden cardiac death. Mutations in mybpc3 are the most common genetic mutations associated with human and feline HCM. To understand how mutations in mybc3 causing sarcomere dysfunction result in the development of non-myocyte phenotypes such as fibrosis, mitral valve anomalies, and microvascular occlusion across species, we generated single nuclei RNA-sequencing datasets from feline, human and murine heart tissue carrying mybpc3 variants. We analyzed these datasets for differential gene expression by genotype for each cell type and assessed changes in cell-cell communication by ligand-receptor analysis. Gene Ontology (GO) enrichment analysis of differentially expressed genes (DEGs) in feline cardiomyocytes revealed alteration in regulation of calcium ion transmembrane transporter activity, regulation of cation channel activity, and extracellular matrix structure and organization, consistent with known phenotypic aspects of HCM such as calcium dyshomeostasis and fibrosis. DEGs in cardiomyocytes of human tissues revealed novel obstruction of cGMP-mediated signaling, protein O-linked glycosylation and negative regulation of cAMP-mediated signaling. DEGs in murine cardiomyocytes affected cardiac muscle thin filament assembly, CDP-diacylglycerol biosynthesis and cell adhesion molecule production. Analysis of intercellular communication in feline and murine hearts revealed an overall loss of ligands broadcast from all cell types, with notable losses from fibroblast cells and cardiomyocytes. These findings are consistent with recent studies implicating altered intercellular communication between cardiomyocytes and non-myocyte cell types as a potential disease mechanism in human HCM. We will further identify common and species-specific disease-promoting pathways in HCM tissue that will allow identification of conserved disease mechanisms that may be targeted in both human and feline disease and will facilitate an understanding of the relevance of mouse models.
Abstract P3052: RNA Binding Protein Csdc2 Is Required For Metabolic And Cardiac Stress Responses
Authors: Jared M McLendon, Xiaoming Zhang, Ryan L Boudreau
Journal: Circulation Research (2023)

Post transcriptional gene regulation (PTGR) mediated by networks of microRNAs and RNA binding proteins (RBP's) controls mRNA processing, localization, and expression. Hundreds of microRNAs and RBPs are expressed in heart, and much remains unknown regarding PTGR’s influence on cardiovascular health and disease. Through bioinformatic analyses, we identified Csdc2 as a cardiac-enriched RBP that is consistently downregulated in failing hearts. Csdc2’s paralog, Carshp1, controls metabolic gene expression in liver through PPARα. We hypothesize that Csdc2 plays key roles in cardio-metabolic stress. To address this, we first assessed mRNA-seq changes in neonatal rat cardiomyocytes after overexpression and knockdown of Csdc2. Pathway analyses revealed reciprocal dysregulation of fatty acid metabolism, ion channels, and cytoskeletal and sarcomere genes. We generated constitutive Csdc2-KO mice, which are viable with no overt baseline phenotypes. Cardiac phenotyping revealed that Csdc2-KO mice have slightly decreased PR interval (~10%, p=1.3e-4, n=16-22) but maintain normal cardiac structure/function. To assess Csdc2’s potential role in metabolic stress, mice were fed a high-fat-diet for 10 weeks and monitored for lean/fat mass and insulin/glucose tolerances. Csdc2-KO mice gained 20% more weight than wildtype littermates (p=0.04, n=13-18) and developed insulin resistance (p&lt;0.01). To test if Csdc2 loss influences cardiac stress, normal chow cohorts were subjected to microsurgery-induced myocardial infarction (MI); Csdc2-KO mice showed ~2-fold increase in mortality within two weeks (70% versus 40% for wildtype). Echocardiographic measures support that Csdc2-KO hearts have larger infarcts, dilation without compensatory remodeling and worse systolic function. Together, these data highlight Csdc2 as a disease-relevant RBP that controls cardio-metabolic stress responses.
Abstract GS.04: Myocardial Tricarboxylic Acid Cycle Suppression Disrupts The Epigenetic Landscape In Human Heart Failure With Preserved Ejection Fraction
Authors: Edwin Yoo, Mohammad Keykhaei, Vivek Jani, Navid Koleini, Alina Guo, Julie S Kim, Simone Sidoli, Kavita Sharma, Virginia S Hahn, David A Kass
Journal: Circulation Research (2023)

Heart Failure with Preserved Ejection Fraction (HFpEF) represents the greatest unmet therapeutic need in cardiology and is intimately related to obesity and metabolic syndrome. Using a bedside-to-bench approach, we investigated the hypothesis that suppressed tricarboxylic acid cycle (TCA) enzymes and metabolic intermediates in HFpEF influence epigenetic histone post-translational modifications (PTMs) that regulate genes involved in mitochondrial OxPhos and fatty acid metabolism. Endomyocardial biopsies were obtained from human HFpEF patients (n=32) and donor controls (n=12) and integrated proteomics, metabolomics, ChIP-seq, and RNAseq analyses were performed. Small molecule histone PTM modulators were screened in vitro in neonatal rat ventricular cardiomyocytes (NRVMs) to identify potential therapeutic targets. Proteomics demonstrates reduced TCA cycle enzyme abundance consistent with our recently published metabolomics data showing reduced succinate, fumarate, and malate. Histone PTM profiling found H3K27ac and H3K36me3 upregulated (p&lt;0.001) and inversely correlated with TCA cycle intermediates succinate and fumerate. ChIP-seq promoter gene ontology analysis revealed enrichment of mitochondrial metabolism and fatty acid uptake ontologies (CD36), as well as major cardiac transcription factors such as GATA4. Small-molecule inhibitor proteomics screens of histone writers in neonatal rat ventricular myocytes showed that H3K27ac inhibition upregulates all TCA cycle enzymes 1.5-4 fold and may rescue TCA cycle function. Our multi-omics approach suggests an association between H3K27ac, H3K36me3, and TCA cycle intermediates. Inhibition of myocardial H3K27ac deposition represents a novel therapeutic target for HFpEF.
Abstract P3110: Sex Differences In Ventricular Tachycardia Ablation In-hospital Outcomes: An Analysis From The National Inpatient Sample Database
Authors: Yasmeen Taha, Ahmad Mahmoud, Mohammed Elzeneini, Mohammed Ruzieh, Carl J Pepine, Zubin Agarwal
Journal: Circulation Research (2023)

Background: There are limited data available comparing outcomes of ventricular tachycardia (VT) ablation in men versus women. Objectives: For patients undergoing ablation for VT, we sought to determine if sex-based differences in outcomes and procedural complications exist. Methods: We queried the National Inpatient Sample (NIS) database between 2016 and 2018 to identify patients aged ≥18 years hospitalized with a primary diagnosis of VT who underwent ablation. Patients with other cardiac arrhythmias or who had an implantable defibrillator/pacemaker placement were excluded. Multivariable logistic regression analysis was performed to assess independent predictors of any procedural complication. Results: Out of 7,200 identified admissions for VT involving VT ablation, 1,280 (18%) were women and 5920 (82%) were men. Men were older (mean age 64.8 vs 57.4 years in women, P&lt;0.01). Comorbidities as prior myocardial infarction (MI), prior CABG, Chronic kidney disease (CKD), COPD, prior cardiac pacemaker, chronic heart failure (CHF) and peripheral vascular disease (PVD) were all significantly more prevalent in men.The primary outcome of in-hospital mortality occurred in 3% of both men and women. Interestingly, the length of stay was longer in men (6.53±4.2 vs 5.26±2.5 days, p&lt;0.01). The incidence of acute MI, acute ischemic stroke, bleeding, need of blood transfusion, tamponade, complete heart block, pulmonary complications, vascular complications similar between men and women, however acute kidney injury occurred more in men (21% vs. 10%, p&lt; 0.001). The overall complication rate was significantly higher in men (28.8% vs 20.7 %, P= 0.0084). The presence of CKD, as well as CHF were independent predictors of any procedural complication (OR 1.27, 95% CI 1.19-1.36, P &lt;0.01) and (OR 1.08, 95% CI 1.03-1.14, P=0.001). Conclusion: Men had higher rates of in hospital complications following VT ablation which might be related to higher rates of comorbidities. There was no difference in in-hospital mortality between men and women. Women represented only 17.8% of VT ablation admissions. Further studies are needed to distinguish the sex-based differences in VT ablation referrals and to compare long term outcomes post ablation.
Abstract P3153: Human Bone Mesenchymal Stem Cell Lentiviral Transduction For The Production Of Extracellular Vesicles Targeted To The Heart Limits Cell Line Expansion
Authors: Cynthia M Xu, Mark Broadwin, Rayane Brinck Teixeira, Frank W Sellke, Ruhul Abid
Journal: Circulation Research (2023)

Objectives: Human bone mesenchymal stem cell derived-extracellular vesicles (HBMSC-EV) have been found to have regenerative and anti-inflammatory effects in heart disease, but one of the main obstacles of this treatment modality is the lack of practical delivery to the heart. To make intravenous delivery possible, this study sought to create a human bone mesenchymal stem cell (HBMSC) that secretes HBMSC-EV which will avoid macrophage uptake and home to the heart through lentiviral genetic modification. Methods: The following HBMSC extracellular genetic modifications were selected: CD-47, an anti-phagocytic marker; cardiac targeting peptide (CTP, sequence APWHLSSQYSRT) and ischemic myocardium targeting peptide (IMTP, sequence CSTSMLKAC), peptides both found to have selective cardiac and ischemic myocardium uptake, respectively, through previous biopanning research. Through a 3 rd generation lentiviral system and subsequent antibiotic selection process, wild-type HBMSC were altered to carry these modifications. Results: Three HMBSC lines were created: 1) CD-47 only, 2) CD-47 and CTP anchored to the outer cell membrane by Lamp-2b, and 3) CD-47 and IMTP anchored by Lamp-2b. Preliminary findings show hindered cell proliferation and adherence - cell doubling time was significantly slowed by passage 6 (versus passage 10 in wild-type HBMSC). Also, the genetically modified HBMSC required a 1:2 subculture ratio (versus 1:3-4 in wild-type HBMSC). Conclusions: These genetically-modified HBMSC, engineered with a goal to be better suited for HBMSC-EV production in the treatment of cardiac disease, have significant limitations in cell proliferation and expansion, which will be a significant obstacle to the production of a meaningful quantity of HBMSC-EV. Ongoing studies are being carried out to characterize changes in HBMSC differentiation and in the cell-matrix.
Abstract P1096: Computational Motion Artifact Removal Acts As Virtual Blebbistatin In Ipsc-derived Cardiomyocytes And Micro-tissues
Authors: Louis Woodhams, Jingxuan Guo, Nathaniel Huebsch, Guy Genin
Journal: Circulation Research (2023)

Introduction: Drugs like blebbistatin that paralyze tissues are critical for accurate optocardiography but directly affect sarcomeres, making it challenging to study structure-function relationships. To overcome this, we applied Direct Deformation Estimation (DDE), a robust strain estimation tool, to enable computational motion removal from videos of beating monolayers and engineered heart tissues formed from human Induced Pluripotent Stem Cell derived cardiomyocytes (hiPSC-CM). Methods: hiPSC-CM and miniaturized engineered heart muscles were stained with the far-red voltage sensitive dye, BeRST-1. Videos of overall motion (bright-field), Ca 2+ (endogenous GCamP6f reporter) and voltage were captured at 100 Hz. Temporal median filtering and Contrast-Limited Adaptive Histogram Equalization were applied as pre-processing steps to improve convergence. The inverse of conformal mappings estimated from DDE were used to “unwarp” videos to artificially reduce motion. Removal of motion was assessed in bright-field videos by performing optical flow analysis. Improvements in optical mapping accuracy were estimated by calculating the spatial distribution of APD 80 (voltage) and time to 75% decay from peak (τ 75 ; Ca 2+ ). Results: Virtual blebbistatin removed &gt;90% of motion from monolayers and engineered tissues without affecting sarcomere architecture (sarcomeric α-Actinin staining), in contrast to chemical blebbistatin. Virtual blebbistatin further reduced spatial dispersion in both APD 80 and τ 75, leading to overall distributions that were less skewed by artificially low repolarization times. Interestingly, when directly assessing Ca 2+ -contraction coupling in plots of motion-corrected Ca 2+ vs. contraction magnitude, we observed that engineered tissues had more uniform and consistent coupling compared to monolayers. Conclusions: Superior uniformity in calcium-contraction coupling of engineered tissues as opposed to monolayers is consistent with observations that engineered tissues are more likely to recapitulate genotype-phenotype relationships and drug responsiveness. Virtual blebbistatin is a promising tool for non-invasive analysis of Ca 2+ -contraction coupling and robust optocardiography.